Sunday, November 03, 2013

Rabbit ears on a green zebra

Ten minutes on the beach; that's all I needed. The weather was miserable, and I wasn't dressed for it; Laurie's feet hurt and I was trying to ignore a migraine. But I had to go to the beach because my critters were getting bored with their store-bought diet. They wanted green stuff, green and soft and salty.

Luckily, the tide was just off the peak and the water was choppy; all along the shore were piles of ripped-up eelgrass, still wet, still fresh. I collected a bagful in my ten minutes. Long blades of eelgrass, sheets of sea lettuce, the durable red Turkish towel, rockweed, delicate red lacy fronds, sugar-wrack kelp, a tall, leafy, bladder-bearing weed, and handfuls of blackish hair; everything newly deposited in a convenient pile for me.

My critters are happy again.

Most of the animals that have the bad luck to be riding uprooted seaweeds at high tide end up dying when the water recedes. I checked my gleanings over carefully, as usual, turning up a few feeble amphipods and a couple of snails.

One of the blades of eelgrass had a brighter green spot on it, barely noticed as I planted the roots in the aquarium. A few minutes later, I saw it again, swimming, and fished it out.

Zebra leafslug, 1 cm. long, on sea lettuce. (I had to fade out the background, almost the same shade as the slug. Good camouflage.)

I had never seen one of these before, but it was easy to find in my Encyclopedia, near the nudibranch section. But it's a sea hare, not a nudi.

The sea hares are related to the nudibranch, the bubble shells, and the aglaja that I've found before, all Gastropods among the Heterobranchia. The bubble shells are like snails that carry their shells mostly inside the body. Nudibranchs have no shells. And sea hares may or may not have shells, which like the bubble shells, they wear under the skin. In the zebra leafslug (aka Taylor's sea hare, or Phyllaplysia taylori) the shell is probably just a small plate, invisible inside the body.

Another difference: the nudibranchs' gills are outside the body cavity, (therefore nudi = nude, branchia = gills). The sea hare's gills are inside. On the photo above, towards the back on the right, there is a projection, like a flap. Sea water enters through a hole on the head end of this flap, and exits on the other.

While I checked him out and looked up info, the leaf slug rested on the sea lettuce in a bowl. He barely moved; I wondered if he was dying after his stressful afternoon, in the waves and in my car. But then I learned that he lives on eelgrass, eating the diatoms and algae that grow there. I put him on a knot of eelgrass in the aquarium and he woke up and started to wander.

"The Zeeb", on eelgrass in the aquarium.

Sea hares got their name long ago, from the two tentacles on the front of the head. They are more like flaps of skin, folded so that they look like rabbit ears. A little back from these are the rhinophores (from rhino = nose, phore = carrier, Greek), those tall white tubes. Zeeb smells with these.

The eyes are at the base of the rhinophores, but probably don't see more than the difference between day and night.

 Zeeb is a youngster, about half his adult size. He's a hermaphrodite, with both male and female organs, capable of fertilizing another leafslug and then laying millions of his/her own eggs. On the eelgrass, of course.

. . . sea hares often forming mating chains of 3 or more animals where the ones in the middle are acting as males and females simultaneously. (http://www.seaslugforum.net/message/17079)

Zeeb's been prowling around the eelgrass and the glass, cleaning up the algae for a day now. I hope the aquarium suits him. I'll have to keep him well supplied with fresh eelgrass. More reasons to go to the beach!

7 comments:

  1. That is true dedication going out on such a blustery day! This new pet for the aquarium is so perfectly camouflaged it would take a very keen eye such as yours to spot it. Hope it gets along well with the other critters. :)

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  2. Wonderful colorful newcomer.

    Good to hear you survived the storm . Wonder if your migraine was triggered by the sharp pressure gradients.

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  3. Very interesting creature, and great photos. I'm forever impressed by your creature collection, and the amazing insights you provide into their lives.

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  4. Hi Susanna!

    I tried leaving a comment before but it might have got deleted as I see you have made many changes.

    I too have an aquariums with critters from boundary bay. Mine is not nearly as old and I would love to pick your brain on some things about it. Do you have an email we could speak over? If you dont wish to post your email on here email me first at ray77k AT outlook.com.

    I look forward to being able to chat with you.

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  5. Hi, Maria! I've been laughing at your peacock cat, on your blog, but can't find a place to comment. So I hope you're reading these replies.

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  6. Ray, I don't know what happened to your previous comment. It doesn't show up anywhere here.

    I've posted my e-mail here before, and there should be a link somewhere in the sidebar, but it also seems to have gotten lost. I'll fix that.

    Anyhow, my address is wanderinweeta - gmail DOT com. I'll watch for your note.

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  7. Upupaepops, that's a thought. Once the weather cleared, I was fine. Thanks.

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I'm having to moderate all comments because Blogger seems to have a problem notifying me. Sorry about that. I will review them several times daily, though, until this issue is fixed.

Also, I have word verification on, because I found out that not only do I get spam without it, but it gets passed on to anyone commenting in that thread. Not cool!

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